The timer divisors are calculated in the (*do_cmdtest) before the (*do_cmd)
is called by the comedi core. The extra sanity checks in the (*do_cmd) are
not necessary, the values returned from i8253_cascade_ns_to_timer() will be
greater than 1. Save the values in the private data so they don't need to be
recalced.
Refactor pcl816_start_pacer() to use the values from the private data.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/pcl816.c | 41 +++++++++++----------------------
1 file changed, 13 insertions(+), 28 deletions(-)
diff --git a/drivers/staging/comedi/drivers/pcl816.c b/drivers/staging/comedi/drivers/pcl816.c
index 9a0b8b6..6cd7154 100644
--- a/drivers/staging/comedi/drivers/pcl816.c
+++ b/drivers/staging/comedi/drivers/pcl816.c
@@ -122,6 +122,8 @@ struct pcl816_private {
unsigned int ai_act_chanlist_len; /* how long is actual MUX list */
unsigned int ai_act_chanlist_pos; /* actual position in MUX list */
unsigned int ai_poll_ptr; /* how many sampes transfer poll */
+ unsigned int divisor1;
+ unsigned int divisor2;
};
/*
@@ -136,9 +138,9 @@ static void setup_channel_list(struct comedi_device *dev,
static int pcl816_ai_cancel(struct comedi_device *dev,
struct comedi_subdevice *s);
-static void pcl816_start_pacer(struct comedi_device *dev, bool load_counters,
- unsigned int divisor1, unsigned int divisor2)
+static void pcl816_start_pacer(struct comedi_device *dev, bool load_counters)
{
+ struct pcl816_private *devpriv = dev->private;
unsigned long timer_base = dev->iobase + PCL816_TIMER_BASE;
i8254_set_mode(timer_base, 0, 0, I8254_MODE1 | I8254_BINARY);
@@ -150,8 +152,8 @@ static void pcl816_start_pacer(struct comedi_device *dev, bool load_counters,
udelay(1);
if (load_counters) {
- i8254_write(timer_base, 0, 2, divisor2);
- i8254_write(timer_base, 0, 1, divisor1);
+ i8254_write(timer_base, 0, 2, devpriv->divisor2);
+ i8254_write(timer_base, 0, 1, devpriv->divisor1);
}
}
@@ -396,8 +398,9 @@ static irqreturn_t interrupt_pcl816(int irq, void *d)
static int pcl816_ai_cmdtest(struct comedi_device *dev,
struct comedi_subdevice *s, struct comedi_cmd *cmd)
{
+ struct pcl816_private *devpriv = dev->private;
int err = 0;
- int tmp, divisor1 = 0, divisor2 = 0;
+ int tmp;
/* Step 1 : check if triggers are trivially valid */
@@ -446,7 +449,8 @@ static int pcl816_ai_cmdtest(struct comedi_device *dev,
if (cmd->convert_src == TRIG_TIMER) {
tmp = cmd->convert_arg;
i8253_cascade_ns_to_timer(I8254_OSC_BASE_10MHZ,
- &divisor1, &divisor2,
+ &devpriv->divisor1,
+ &devpriv->divisor2,
&cmd->convert_arg, cmd->flags);
if (cmd->convert_arg < 10000)
cmd->convert_arg = 10000;
@@ -472,33 +476,14 @@ static int pcl816_ai_cmdtest(struct comedi_device *dev,
static int pcl816_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
{
struct pcl816_private *devpriv = dev->private;
- unsigned int divisor1 = 0, divisor2 = 0, dma_flags, bytes, dmairq;
struct comedi_cmd *cmd = &s->async->cmd;
+ unsigned int dma_flags, bytes, dmairq;
unsigned int seglen;
if (devpriv->irq_blocked)
return -EBUSY;
- if (cmd->convert_src == TRIG_TIMER) {
- if (cmd->convert_arg < 10000)
- cmd->convert_arg = 10000;
-
- i8253_cascade_ns_to_timer(I8254_OSC_BASE_10MHZ,
- &divisor1, &divisor2,
- &cmd->convert_arg, cmd->flags);
-
- /* PCL816 crash if any divisor is set to 1 */
- if (divisor1 == 1) {
- divisor1 = 2;
- divisor2 /= 2;
- }
- if (divisor2 == 1) {
- divisor2 = 2;
- divisor1 /= 2;
- }
- }
-
- pcl816_start_pacer(dev, false, 0, 0);
+ pcl816_start_pacer(dev, false);
seglen = check_channel_list(dev, s, cmd->chanlist, cmd->chanlist_len);
if (seglen < 1)
@@ -546,7 +531,7 @@ static int pcl816_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
enable_dma(devpriv->dma);
}
- pcl816_start_pacer(dev, true, divisor1, divisor2);
+ pcl816_start_pacer(dev, true);
dmairq = ((devpriv->dma & 0x3) << 4) | (dev->irq & 0x7);
switch (cmd->convert_src) {
--
1.8.5.2
_______________________________________________
devel mailing list
devel@xxxxxxxxxxxxxxxxxxxxxx
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
